Problems of robotic welding of C35 steel without pre-heating

Abstract

Automated production has become a prerequisite for meeting the strict demands of most manufacturers in the automotive industry. Such production relies on two key parameters for effective planning and monitoring: cycle time and overall equipment effectiveness. Any issues or problems within the production process impact these parameters, while causes for them can be diverse. This paper presents analysis regarding some of them in case of robotic GMAW welding of components made of dissimilar steels. Emphasis is placed on the weldability of the more critical base material, C35 medium-carbon steel, for which preheating is commonly applied prior to welding in order to reduce the risk of hot cracking. However, due to specifics of the production process considered in this study, preheating is omitted. Instead, welding is performed immediately following tempering and cleaning operations. The paper analyses the reasons leading to hot crack formation in the investigated component and gives recommendations for their prevention.